Tool for detecting included angle of axes of flanges

The invention relates to a tool for detecting an included angle of axes of flanges. The tool includes a first iron sheet and a second iron sheet; one end of the first iron sheet is movably hinged to one end of the second iron sheet; the first iron sheet and the second iron sheet are aligned to axes of two flange joints respectively to detect the included angle, a distance between the two iron sheets is figured out according to a trigonometric function or is directly detected, and a criterion is used to determine whether the installation of the two flange joints is qualified or not. According to the invention, the tool has a simple structure, is low in manufacturing cost, is easy to operate, and can quickly and accurately determine whether the installation of the two flange joints is qualified or not.